This application is a national stage of PCT/EP00/03895 filed Apr. 29, 2000 and is based upon German national application 199 50 101.7 of Oct. 18, 1999 under the International Convention.
This invention relates to a process of introducing granular solids into a pressure vessel under a pressure of at least 2 bar, wherein the solids first of all reach a first container under atmospheric pressure and then a second container of variable pressure, which is disposed thereunder, before they are introduced into the pressure vessel, and wherein the first and the second container each have a lower outlet passage and a movable shutter cooperating with the outlet passage.
Sluice devices of this kind, which employ movable shutters, are known and described for instance in U.S. Pat. No. 5,584,970. In these devices, however, small amounts of gas always flow from the pressure vessel to the container under atmospheric pressure and from there into the atmosphere, which in certain cases can be very disadvantageous.
It is therefore the object underlying the invention to design the above-mentioned process such that without a significant wear solids can be introduced into the pressure vessel without gases reaching the atmosphere countercurrently with respect to the solids.
In accordance with the invention this object is attained in that the outlet end of the outlet passage is 20 to 400 mm above the shutter in the closed position, that in the closed position the shutter forms the bottom of a chamber at least partly filled with solids, that the chamber is connected with the outlet passage in a gastight way and there is no gastightness between the chamber and the shutter, that in the closed position the shutter carries a solid bed and a vertical solid column having a height of at least 1 m is present in the outlet passage and in the container, and that in the closed position seal gas is pressed into the chamber and into the solid column from the outside. This locking process is particularly useful for hot solids, which are introduced into the first container for instance with temperatures in the range from 300 to 1300xc2x0 C.
Expediently, the shutter and at least in part also the chamber are disposed in a shutter housing which includes the solids inlet for the container disposed thereunder.
It is usually ensured that in the closed position the solid bed in the chamber has a minimum height of 5 mm, so that the area between the edge of the chamber and the shutter becomes largely impermeable to gas.
The pressure in the pressure vessel preferably lies in the range from 3 to 20 bar. The gas in the pressure vessel may be of completely different kinds, it may for instance have a toxic effect or it may consist of hydrogen for at least 50 vol-%, so that it must be prevented from coming in contact with the oxygen of the air.